Clara (Jenna-Louise Coleman) and the Doctor (Matt Smith) burst in on a ghost-hunting session at Caliburn House in 1974. Behaving in a brash but mysterious fashion allows them to insert themselves into this event and into the lives of a semi-retired war hero and spy (Dougray Scott), and his empathic, psychic medium assistant (Jessica Raine).

Their ghost turns out to be an early time traveler (Kemi-Bo Jacobs) who has dropped into a pocket universe. Although her presence is stretched across the entire existence of Earth, she has only experienced a few seconds due to the time differential.

Everyone is rescued, of course, but the Doctor's real purpose for visiting is to get a psychic opinion on Clara. He is told that Clara is an ordinary girl, more frightened than she lets on. Clara is told not to trust the Doctor because "there's a sliver of ice in his heart."

POINTS OF INTEREST1. Clara is still without a TARDIS key, resulting in a confrontation with the TARDIS and her Voice Visual Interface, which uses Clara herself as avatar.

2. The TARDIS's use of Clara as the visual representation she is most likely to trust only confirms Clara's opinion that the TARDIS does not like her, echoing the thought first mentioned in "The Rings of Akhaten."

3. Once more, Clara mentions being afraid, as she did in Cold War. Emma repeats this as well. We get it, traveling with the Doctor is a little unnerving. Enough talk about that now, thanks.

WHAT WORKED
The retro-techno-ghost hunter trappings were great fun, and the Doctor's mysterious Ministry guy interaction with Alex especially so.

Like the commander of the first Mars base, Hila Tacorian is a pioneer--- time travel in Hila's case--- and a fixed point in time made more mysterious by the Doctor's participation. Also a girl, which is nice.

Emma, defying the delicate, psychic stereotype to go above and beyond to save Hila and the Doctor was joyful to see, which is why Clara's act of bravery was actually somewhat disappointing. There's Emma frying all her brain circuits trying to give the Doctor a chance at getting back, and Clara has convinced the TARDIS to do a suicide run with her. There really doesn't need to be three women courting death for him all at the same time.

WHAT DIDN'T WORK
While, in the end, the ghost had a reasonable science fictional explanation, the wait getting there was too long. The red herrings such as the cold spot and the wackiness with the chalk circle were not explained by the time travel and pocket universe. Previously disappointed by magical potions in "The End of Time Part I" and the like, it was just too little, too late to break out the space suits.

I am dead tired of the destined in the stars True Lovers with no real barrier to their relationship doing a pointless dance of approach and retreat. Not that Emma and Alex needed to grab one another and sink below frame as soon as they are introduced, but neither should have had any doubts about the feelings of the other considering the strength, especially the empath.

I know that time is supposed to be moving strangely there, and it is an alien pocket universe thing, but "The Crooked Man" (Aidan Cook) moved like Harryhausen early test footage, far below modern effects expectations.

While the extra creature explains the mysterious extra hand business, they should have addressed it earlier. Making a second trip into deadly peril for kicks just sapped all the energy from the main climax and denouement and wasted time that could have been better used getting to know Hila.